IGPP Seminar Series

Issues in Interacting Strike-Slip Faults

by David Oglesby
UC Riverside

Abstract

One of the pressing issues in seismic hazard analysis is the probability of earthquake rupture jumping between fault segments, resulting in a large cascading event. Researchers (e.g., Wesnousky, 2006) have conducted observational surveys to determine the maximum width of stepover that rupture may jump in strike-slip systems, and other researchers (e.g., Harris et al., 1991; Kase and Kuge, 1998; Harris and Day, 1999) have used numerical methods to study the dynamics of such systems. Both methods imply that ruptures have difficulty propagating across stepovers with widths greater than 3-4 km, with possible differences between compressional and dilational stepovers. The present study extends the numerical modeling work above to address some remaining questions, such as 1) How does the method of rupture termination on the primary segment affect the ability of rupture to jump to the secondary segment? and 2) How do assumptions about the normal stress dependence of friction affect the dynamics of such systems? The results may have implications for seismic hazard in near multi-segment strike-slip systems.
Tuesday, 22 May 2007
3853 Slichter Hall
Refreshments at 3:45 PM
Lecture at 4:00 PM